Question

a 25.0 mL sample of HCl is neutralized by 26.5 mL of 0.155M NaOH. Calculate the molarity of the HCl solution. (Hint:In this case, molarity of HCL is Ma(molarity of acid) in moles/liter of HCl.)

HCl +   NaOH                 -->         NaCl         +        H2O

Answer 1

Let V1=volume of Hcl=25.0ml=25.0/1000 L=0.025 L

V2=volume of NaOH=26.5ml=26.5/1000L=0.0265 L

M1= molarity of HCl

M2=Molarity of NaOH=0.155M=0.155 mol/L

Also from the given che,mical equation

HCl +   NaOH     =       NaCl         +        H2O

1 mole HcL reacts with 1 mole of NaOH

So use formula

M1*V1=M2*V2

M1=M2*V2/V1=0.155mol/L* 0.0265 L/0.025 L=0.1643 mol/L =0.1643M (answer)